The Mariana Trench's Challenger Deep—the deepest point on Earth—looks as bleak and barren as the moon, according to James Cameron, who successfully returned just hours ago from the first solo dive to the ocean abyss.

At noon, local time Monday (10 p.m. ET Sunday), the National Geographic explorer and filmmaker's "vertical torpedo" sub broke the surface of the western Pacific, some 200 miles (322 kilometers) southwest of Guam.

After a descent that took roughly two and a half hours, Cameron spent about three hours conducting the first manned scientific exploration of Challenger Deep.

For his return trip, Cameron experienced a faster-than-expected, roughly 70-minute ascent, which he described as a "heckuva ride."

Bobbing in the open ocean, his custom-designed sub, the DEEPSEA CHALLENGER, was spotted by helicopter and plucked from the Pacific by a research ship's crane.

Cameron said this morning during a post-dive press conference held aboard the Octopus, a yacht owned by Microsoft co-founder Paul Allen, a longtime Cameron friend. (Allen was on the scene for the historic dive and posted live updates of the event on Twitter from aboard his yacht, which provided backup support for the mission.)

You just gotta love wealthy adventurers. Makes me wonder why no government ever cared to see what lies at the bottom of the world?